John baird



(No Model.)

J. BAIRD.

COMPOUND STEAM ENGINE.

No. 447,929. 9 Patented Mar. 10, 1891.

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Niran STATES PATENT Fries.

JOHN BAIRD, OF NEV YORK, N. Y.

COMPOUND STEAM-ENGINE.

SPECIFICATION forming part of Letters Patent No. 447,929, dated March 10, 1891.

Application filed November 24, 1890. Serial No. 372,517. (No model.)

To all whom, it muy concern:

U Be it known that I, JOHN BAIRD, mechanical engineer, a citizen of the United States, residing in New York city, county, and State, have invented vcertain new and useful Improvements in Compound Steam-Engines, of which the following is a specification.

My invention relates to the tandem class of compound engines in which the steam-cylinders are arranged end to end in the same axial line; and its object is to permit of the ready insertion or removal of the pistons. This end I attain by connecting both pistons with a single piston-rod extending entirely through both cylinders and inclosed in tubular sleeves held in position by a nut.

My improvements, while applicable to all classes of compound engines, are especially applicable to those of locomotives, and are so shown in the accompanying drawings, which show so much of a locomotive to which my improvements are applied as is necessary to illustrate the subject-mattei' which is. hereinafter specified, the parts not otherwise indicated being of usualwell-known construction.

Figure l is a side view of the forward end of a locomotive; Fig. 2, a plan thereof, and Fig. 3, a longitudinal section through the cylinders, on an enlarged scale. Fig. 4 is asimilar section through the pistons and pistonrods, showing a modification.

A standard locomotive A is shown as supported on a front truck B. Cylinders C D are secured on each side of the engine-frame in the same axial line, the high-pressure cylinders C being in front of, abutting against, and directly connected with the front heads D2 of the low-pressure cylinder. The pistons C D are connected by a piston-rod E, passing entirely through both cylinders and sliding through stuffing-boxes d CZ cin their heads or covers. The front head C2. of the highpressure cylinder and the rear head D3 of the other one are made removable to afford access to the pistons. The rear end of the pistonrod is shown in Fig. 3 as made of larger diameter than its front end, and tapers at the point where it passes through the rear piston. A tube o1` sleeve e encircles the reduced portion of the piston-rod between the two pistons, which abut against its ends, and are thus kept the required distance apart. A similar sleeve e also encircles the piston-rod between the forward piston and the front end of the piston-rod, and is secured in place by a nut e2 outside the cylinder. The parts are t-hus securely clamped together, but can readily be separated by unscrewing this nut, after which, the cylinder-heads C2 D3 being removed, the piston-rod and rear piston can be withdrawn through the rear end of the larger cylinder, while the sleeve and front piston are drawn out through the front end o f the smaller cylinder. The rear end of the piston-rod is connected with a cross-head F.

Fig. 4: shows a piston-rod E, of uniform diameter, extending through both pistons, which are maintained the proper distance apart thereon by inclosing sleeves or thimbles e e e3, interposed between the pistons and between them and the cross-heads F and nut e2, as above explained. Under this organization the sleeves themselves slide through theirrespective stuffing-boxes and constitute the bearing-surfaces of the piston-rods.

Anapplication led by me November 19, 1890, SerialNo. 371,964, shows suitable valves, link -motions, dac., which may be used in connection with the improvements herein claimed, which dii-fer from the corresponding parts claimed in that application.

I am aware that a sleeved piston rod protruding through a cylinder is old, and do not, therefore, broadly claim such construction; but so far as I am aware I am the first to arrange two cylinders end to end, with a piston-rod connecting both pistons, protruding through both cylinders, and provided with loose or removable spacing thimbles or sleeves held by a nut outside the cylinders, thus affording ready access to both cylinders and their pistons by removing their outer heads and the nut. n

I-laving thus fully described the construction, organization, and operation of my iinproved compound steam-engine, what I claim therein as new and as of my own invention is l. The combination, substantially as hereinbefore set forth, of cylinders abutted end to end in the same axial line, their pistons, a single piston-rod extending through both pistons and through both cylinders, a cross-head at one end of the rod and a nut at the other,

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